A loading machine, for example an industrial loader, typically has a loader bucket and linkages for providing the bucket with loading positions, transporting positions, and dumping positions, etc. An operator of the loading machine, typically located at a cabin that is on the top of the loading machine, may have difficulty in properly positioning the bucket when the bucket is at a “low level.” Particularly, when the bucket is at a loading, stripping or cleaning up position, which requires the bottom surface of the bucket being aligned with a ground surface, the bottom of the bucket is invisible to the operator. As a result, the operator may improperly position the bucket, such as in an oblique position with respect to the ground surface. Correcting for a better angle of the bucket wastes time and reduces the overall efficiency of the loading machine. Therefore, a bucket design which improves the operator's feel for the position of the bottom surface of the bucket may be desired for improving the overall efficiency of the loading machine.
U.S. Pat. No. 4,604,025 (the '025 patent) issued to Hammoud describes a position indicator for a material handling element (e.g., a bucket) of a machine. The position indicator in the '025 patent includes a plate pivotally attached to the material handling element in line with an operator's line of sight from the cab towards the material handling element. The plate has first indicia on an edge facing the operator, second indicia on a top surface of the plate, and third indicia on a bottom surface of the plate. When the material handling element is disposed at the predetermined angle during operation of the machine, the operator will only view the first indicia. Thus, during operation, if the operator only sees the first indicia, he may know that the material handling element is at the predetermined angle. If, on the other hand, he sees either the second or third indicia, he knows that the bucket is inclined relative to the predetermined angle, and he may adjust the bucket until he only sees the first indicia.
Although the position indicator of the '025 patent may provide the operator a sense of the level position of the bucket, because the line of sight from eyes of an operator to the position indicator varies for different operators, depending on the height of the operator, the position indicator needs to be adjusted each time a different operator drives the loading machine. Even for the same operator, he may change sitting positions from time to time, and his line of sigh may change, and that may often result in misalignment of the bucket with the predetermined angle if the operator keeps relying on the position indicator he set in his initial sitting position.
The present disclosure is directed to solving one or more of the deficiencies discussed above.